<!DOCTYPE html>
<html>
  <head>
    <title>斌斌学院任务七</title>
    <script src="traversal.js"></script>
	<link href="style.css" type="text/css" rel="stylesheet">
  </head>
  <body class="stop">
    <div class="parent" id="parent">
	  <div class="item1">
	    <div class="item2">
		 <div class="item3">
		  </div>
		  <div class="item3">
		  </div>
		</div>
		<div class="item2">
		  <div class="item3">
		  </div>
		  <div class="item3">
		  </div>
		</div> 
	  </div>
	  <div class="item1">
	    <div class="item2">
		  <div class="item3">
		  </div>
		  <div class="item3">
		  </div>
		</div>
		<div class="item2">
		  <div class="item3">
		  </div>
		  <div class="item3">
		  </div>
		</div>
	  </div>
	</div>
	<form>
		<input type="button" value="前序遍历" id="qian">&nbsp;&nbsp;
		<input type="button" value="中序遍历" id="zhong">&nbsp;&nbsp;
		<input type="button" value="后序遍历" id="hou">&nbsp;&nbsp;
		<input type="button" value = "清除" id = "clear">
	</form>
	
  </body>
</html>